Circuit breaker



1954 F. GELZHEISER CIRCUIT BREAKER Filed April 12, 1952 2 Sheets-Sheet 2Fig.3.

WITNESSES:

Francis L.Ge|zheiser.

Patented Feb. 16, 1954 UNITED STATES PATENT OFFICE CIRCUIT BREAKERFrancis L. Gelzheiser, Pittsburgh, Pa., assignor to WestinghouseElectric Corporation, East Pittsburgh, Pa., a corporation ofPennsylvania Application April 12, 1952, Serial No. 281,981

11 Claims. 1 This invention relates to circuit breakers and moreparticularly to circuit breakers for controlling lighting and moderatepower circuits.

An object of the invention is to provide a circuit breaker which is ofsimple and rugged construction, safe and reliable in operation, andwhich is inexpensive to manufacture.

A second object of my invention is to provide a trip-free circuitbreaker operated by a toggle which is normally supported at its knee bya member movable in response to an overload to permit collapse of thetoggle and opening of the contacts independently of the handle.

Another object of the invention is to provide a circuit breaker in whichthe movable switch i.

member forms a part of the operating toggle sup ported in an undersetoperative position by a pivoted trip member which is actuated by storedenergy means to effect automatic opening of the breaker.

Another object of the invention is to provide a circuit breakerembodying a trip member which is actuated by stored energy means tocause opening movement of a movable switch member, the trip memberhaving means thereon for engaging and starting the switch member inopening direction.

Another object of the invention is to provide a circuit breakerembodying a stored energy trip device which is releasably restrained bya then be best understood from the following detailed descriptionthereof when read in conjunction with the accompanying drawings.

In said drawings:

Fig. 1 is a side elevational view with the cover removed of a circuitbreaker embodying the principles of the invention, the breaker beingshown in the closed-circuit position;

Fig. 2 is a view similar to Fig. 1 but showing the parts in themanually-opened position;

Fig. 3 is a view similar to Fig. 1 but showing the parts in thetripped-open position;

Fig. 4 is a horizontal sectional view taken along line IV-IV of Fig. 1.

Referring to Fig. 1 of the drawings, the circuit breaker comprisesgenerally a housing H and a cover plate I3 (Fig. 4) both of moldedinsulating material, stationary contact means and cooperating movablecontact means 11, an operating mechanism indicated generally at IS and atrip device indicated generally at 2!.

The stationary contact [5 is rigidly mounted on the inner end of anangular conducting strip 23 which extends out through an opening in theadjacent end wall of the housing H and has a terminal connecting means25 at the outer end thereof. The movable contact I! is rigidly mountedon one end of a switch actuating member 2! having its other endpivotally connected by means of a knee pivot pin 29 to a pair of spacedtoggle links 3| pivotally mounted on a pivot pin 33 supported incompanion openings in the side wall of the housing II and in the coverplate I3. The toggle links 3| form an underset toggle with the switcharm 21. The switch actuating member 21, at a point adjacent the pivotpin 29, is connected by means of a flexible conductor 35 to a bimetaltrip element 31 which is mounted by means of a screw 39 on one end wallof the housing II. The other or free end of the bimetal element isconnected by means of a flexible conductor M to the inner end of aconducting strip 43 which extends through an opening in the end wall ofthe housing H and has a terminal connector 45 on its outer end.

A pair of overcenter springs 41 disposed one on each side of the switchmember 21 has one end hooked over a pin 49 in the switch member and theother end connected by means of an extension 5| to an arcuate operatinghandle 53. The handle 53 is disposed for sliding movement in an arcuategroove 55 in the housing l I and in a companion groove (not shown) inthe cover plate [3. The handle 53 is of molded insulating material andhas a finger piece 5'! molded integral therewith which extends outthrough an opening 59 in the housing II.

In the closed position of the parts, a projection 6| on the switchmember 21 adjacent the knee pivot pin 29 is held in engagement with theperiphery of a trip member 63 by the overcenter springs M which areovercenter to the right of the knee pivot pin 29. In this position, thesprings 41 bias the switch member 2'! closed. The trip member 63 is madeof molded insulating material and is pivotally mounted by means oftrunnions 65 molded integral therewith which engage in companionopenings in the side wall of the housing 5 l and in the cover plate !3.The trip member is biased to the position shown in Fig. 1 by means of aspring 6'! disposed in a notch in the cover plate I3 (Fig. 4) andengaging a flat portion of the adjacent trunnion 65.

Molded integral with the trip member 63 is a projection 69, the free endof which, in the normal or closed position of the trip member, liesadjacent and in the path of movement of one end of a trip actuator TH.pivotally mounted on a pin 13 supported in openingsin the side wall ofthe housing H and in the cover plate IS. The trip actuator H is biasedin a counterclockwise direction about the pin 13 by means of a spring 15connected under tension between the trip actuator H and a pin Hsupported in thehousing The trip actuator fll is nor- H and cover l3.

mally releasably restrained by engagementof a, I

latching end '59 thereof with a latch member threadedly comprising anadjusting screw Bl mounted in the bimetal element 31.

All of the parts, except the bimetal element, are removably mountedthrough the, open side ber 63 under the influence .of the spring willcause a projection 93 on the trip membergto strike a portion 95 of theswitch member 21 and start the switch member in opening direction. Theparts are shown in the automatically tripped open position in Fig. 3.

Before the contacts can be closed following an automatic openingoperation, it is necessary to reset the tripmember 63 to its operativeposition ,iFig. 1) and to reset and relatch the trip of the housingglland, are supported andjposi-f, tioned'i'n' the housing by. means ofsurfaces and recesses, moldediin the housing .H and in the cover i3Without being positively "fastened to' the housing or cover.

The. circuitbreakerv is manually opened by manipulationofthe handle53. 1Movement of 11.

handletoWard theleftfrom theposition m which it appearsin Fig, .1 .to.its Fig, 2 position carries the. linelof action {of .thejoyercenterSprings 4!! over to the...1eftjyoi thejpivot pin 29 where the. lovercenter springsv bias the switch member 27 I in opening directionand' ,move the switch mem-' ber clockwise,aboutthepivot 29 to open, theconj- I tactswith a'isnap action. Theopening movementjo'f ,the switchmemberis limited by means '1 of ajstopjtii moldedintegraljwith'thie baseof th e housing IL The parts fareshown in the manually opened positionjin Fig. 2

The; contacts are closed by reverse movement of the han dle 53 from theposition shown in Fig. 7 2 back'lto. the closedposition. This movementof -thehandle carries the line of action of the ov ercenter springs sl'acro'ss to thefrightof the pivot pin 29 whereupon thegovercenter springsmove H theswitch arm 2.! tothe closed position to close 7 t contacts wth asnapact ony The circuit breakeri'strippedopen automatically'bythermal bendingof the'bimetal element 31 when heated in.response tooverload currents,

Upon thejoccurrencejof an overload current/5 74c 1 birrietal element 3'lbecomesheated and, when.

heated a. predetermined amount bends toward. the left .(Fig 1) causingthe latch 6| to release the "trip actuator "ii whereupon the spring 15 jv snaps the trip actuator counterclockwise about its pivot 73 against alimit stop projecting inwardly'from the cover plate i3. This movement ofthe trip actuator 7 [acts on the projection 69 of the trip member 63 tosnap this member clockwise to theposition shown in Fig. 3, during'whichmovement a recess 81 in the trip member 63 is moved to a position"beneath the projection 6| on the s'witch member 27. f At this time, acomponentjof theff orce of the overcenter springs 4? cause's'the'projection 6i to move into the recess 81 which action carries the kneepivot pin'ZS acrossf to the right of theline of action of the overcentersprings. Thi s cansescollapse of the: toggle l'l- -ti and movement ofthe switch member :21 to thefopen positiontoopen thecontacts Iwithasna'p action. Atthe same time, the'proiection Bl ,moyes into therecess 8'! the springs 41 move the'swit ch member12'l upward1ycausing:.

actuator "ll This "is accomplished by movement of thehandle 53 to theopen position as shown in Fig. 2. During this movement the projection 9!on the handleengages, the projection fiil on thistripmember 63 androtates this mem b'e I." counterclockwiseiio its Fig- 2 1 051 nd ilnsgyi$3 causes the pro-*1 movement of the trip member jection S3 thereon toengage the trip actuator fl l and move the latter clockwise to itslatched posi During the latter'portion oi this move-', ment, thebeveledlatch end ls of thetrip actua tor wipes by the latch member 81slightly bending the bimetal element 37. Thereafterthe bimetal elementresumes its normal position re engaging thelatch 3i withthe' latch end;13 pf tion.

the trip actuator ll. Also; during the counte clockwise resettingmovement of 4 the ,trip mern ber (555, a camsuriace 91 at the filli'ofthe'recessfii in the trip, member engages the'pro'jection fii on theswitch member 2'! and moves the kneecf the toggle 21--3i to the positionshown in Fig. 2.

wherev the projection 65 rests on the annular p e-' riphery oi the tripmember 63. This moves the;

knee pivot pin 29 to the left to its Fig, 2 position The contacts arethen closed in the previously described manner by movement of the handlej 53 rom theposition shown in Fig. 2 back to the- Fig.1 position.

The invention provides a circuit breaker in which the movable switchmember forms a part of the operating toggle and is supported inoperative position by a pivoted trip member." The trip member isactuated to effect automatic opening of the contacts vby astored energymeans which is released by a thermallyresponsive trip device. The tripmember is provided with means actuated. bythe stored energy means forengage 1 ing and starting. the switch member in opening,

direction should the contacts stick.

Having described the invention in accordance, with the'provisions of thepatentstatutes, it is to be understood that various changes. and modiiications may be made in the structuraldetails and arrangement of partsthereof withoutfde; parting from some of the essential. features of fthe invention.

I claim as my invention;

A circuit breaker comprising stationary and: movable contacts, a.mcvableswitch actuating.-

member for actuating said movable contact. a link havingone endpivotallymounted on a fixed pivot. and the other end pivotally connected to one,

end of said switch actuating .meri ber to iorm a. toggle, a trip m embernormally sup-porting said se ei ope at e o t n. on Opera i g. nd

movable to an open position andfto a closed P95 1 ma .qv rcep er s in ci i vc vsceeeqispl between said handle; and said switch actuatingmember, said overcenter spring being operable by said handle to causeopening and closing movement of said switch actuating member, a storedenergy device releasable to actuate said trip member to a position topermit collapse of said toggle and automatic opening of said contacts,and a trip devic operable to effect release of said stored energydevice.

2. A circuit breaker comprising stationary and movable contacts, amovable actuating switch member for said movable contact, a link havingan end pivotally mounted on a fixed pivot and the other end pivotallyconnected to one end of said switch actuating member to form a toggle, aro-' member releasable to rotate said trip member to 5 a second positionin which said trip member permits collapse of said toggle to effectautomatic opening movement of said switch actuating member, a tripdevice operable in response to overload currents to release said springoperated member, and a portion on said handle for engaging and rotatingsaid trip member back to said first position.

3. A circuit breaker comprising stationary and movable contacts, amovable switch member mounting said movable contact at one end, a linkhaving one end pivotally mounted on a fixed pivot and the other endpivotaliy connected to the other end of said switch member to form atoggle, a rotatable trip member having a first position in which itcooperates with the knee of said toggle to normally restrain said togglein an operating position, an operating handle movable to an openposition and to a closed position, an overcenter spring connectedbetween said handle and said switch member and movable overcenter bysaid handle to cause opening and closing movement of said switch member,a spring operated member releasable to engage and rotate said tripmember to a second position in which said trip member permits collapseof said toggle to effect automatic opening of said switch member, a tripdevice operable in response to overload currents to release said springoperated member, said handle when moved to said open position engagingand rotating said trip member back to said first position, and aprojection on said trip member for engaging and resetting said springoperated member.

4. A circuit breaker comprising stationary and movable contacts, amovable switch member mounting said movable contact at one end thereof,a link having one end pivotally connected to the other end of saidswitch member to form a toggle therewith and having its other endpivotally mounted on a fixed pivot, a rotatabl trip member having afirst position in which it restrains said toggle in an underset positionand rotatable to a second position to permit collapse of said toggle andautomatic opening movement of said switch member, operating handlemovable to an open position and to a closed position to effect openingand. closing movement of said switch member, an overcenter springconnected between said handle and said switch member, and operable tocause opening and closing movement of said switch member, a biasedreleasable member operable when released to engage and rotate said tripmember to said second position to permit collapse of said toggl andautomatic opening movement of said switch member, a projection on saidtrip member for engaging said switch member and starting said switchmember in opening direction, and a current responsive trip deviceoperable in response to overload currents to release said biased member.

5. A circuit breaker comprising stationary and movable contacts, amovable switch member mounting said movable contact at one end thereof,a link having one end pivotally connected to the other end of saidswitch member to form a toggle therewith and having its other endpivotally mounted on a fixed pivot, a rotatable trip memher having afirst position in which it restrains said toggle in an underset positionand rotatable to a second position to permit collapse of said toggle andautomatic opening movement of said switch member, an operating handlemovabl to an open position and to a closed position to effect openingand closing movement or said switch member, an overcenter springconnected between said handle and said switch member, and operable tocause opening and closing movement of said switch member, a biasedreleasabl member operable when released to engage and rotate said memberto said second position to permit collapse of said toggle and automaticopening movement of said switch member, a projection on said trip memberfor engaging said switch member and starting said switch member inopening direction, a current responsive trip device operable in responseto overload currents to release said biased member, and a projection onsaid handle for engaging and rotating said trip member back to saidfirst position.

6. A circuit breaker comprising stationary and movable contacts, amovable switch member mounting said movable contact at one end thereof,a link having one end pivotally connected:

to the other end of said switch member to form a toggle therewith andhaving its other end pivotally mounted on a fixed pivot, a rotatabletrip member having a first position in which it restrains said toggle inan underset position and rotatable to a second position to permitcollapse of said toggle and automatic opening movement of said switchmember, an operating handle movable to an open position and to a closedposition to effect opening and closing movement of said switch member,an overcenter spring connected between said handle and said switchmember and operable to cause opening and closing movement of said switchmember, a biased releasable member operable when released to rotate saidtrip member to said second position to permit collapse of said toggleand automatic opening movement of said switch member, a projection onsaid trip member for engaging said switch member and starting saidswitch member in opening direction, a current responsive trip deviceoperable in response to overload currents to re lease said biasedmember, a projection on said handle for engaging and rotating said tripmemher back to said first position, and a second projection on said tripmember for engaging and resetting said biased member.

'7, A circuit breaker comprising a switch member movable to open andclose the circuit, a link having one end pivoted on a fixed pivot andthe other end pivotally connected to one end of said switch member toform a toggle, a trip member having; as. plurality of; projectionsthereon and 3 having: a: surface thereon: normally engaging 1 collapseof said toggle, an operating handle mov-- able-toran open position andto aclosed position togefiectiopening-and closing. movements of saidswitch member, an overcenter spring having one end zconnected: tosaid:handle and the other end connected to sa-id switch member'for operatingsaid :switch: member; a" releasable biased member operable-whenreleasedto engage one of said projections andmove said trip membertosaid positionitospermit-collapse of said toggle and openingamovementof said switch member, said biasedimember. causing another of saidprojections. tozengage said switch member and start saidx switch:member' in opening direction, a trip device operable to release saidbiased member; said :handleengaging a. thirdprojection on said trip;-memberand resetting said trip member,

saidsione projection during said resetting move ment engaging andresetting said biased member, andisaid trip. member during saidresetting movement moving the knee of said toggle to saidoperative-position.

8:= .A .circuit breaker comprising relatively movable::contacts,='ajswitch actuating member movable'ator effect openingandclcsing of saidcontacts; .ai linki-.havingone (end pivotally mounted onia'fixedzpivotiandthe:other end connected. tosone. end vofqsaid switch;actuating member ,to

form a: toggle, a trip:.member cooperating with the kneelof:saidi=toggle to"normally restrain said toggle: in: an 1 operativeposition, an. operating handle.) movable to an open.- positionv and. to

a closed position to effect manual operation.

of said? switchactuating "member; an; overcenterrspring connected?between said :handle andsaid'aswitch actuating" member; .said?overcenter spring :being' movable :overcenter. by said handie" to causeopening and closing. movement of said: switch actuating memberv aboutthe knee of; said 1 toggle, saidtrip member. main taining the-knee of:said toggle stationary during said manual operationof said switchactuating. member, a;.stored' energy device releasable to.

engagerand actuatelsaid.trip member to a-position. to permit movement ofthe knee .0131 said toggleand collapseof said toggle toefiect auto--matic open-ing movement of said switch actuating memberland openingofysaid contacts, and a trip device-.operable-to efiect releasaof saidstored.

energy devices.

9." Acircuit breaker comprising relatively movable -contacts,.- aswitchactuating member. moV- ableto effectopeningand closing of saidcontacts, .a-linkhavingone end pivotally supported on-a-fixed pivot andthe other end pivotally connected to said switch actuating member toform a togglean operating handle movable to an open position and to aclosed position toeifect manual.

opening and closing of said contacts, an overcenter. spring connectedbetween said handle and said switchractuating member, said overcenterspringbeing movable overcenter across the knee .ofsaid toggle to causeopening and clos ing movement of said switch actuating member about. theknee of said toggle, a trip member normally restraining. said togglein.an operative position iandholding the knee of said toggle statoggle-inan operative position, said'trip'member position and to a, closedposition to manuallyopen and close saidcontacts; an overcenter; springhaving one end connected to said handle; and the other end connected tosaid switch. 34.61311 ating .member operable by-said handle to;-cause-.; opening and closing movement of said switch": actuatingmember, a rotatable trip memberhavr inga first'positionin which itcooperatesiwithf;

the knee of said toggleto normallyrestraintsaids togglein an operativeposition; said trip; members" in said first position restraining theknee of said a toggle stationary during manual operation-of said switchactuating member, a spring operated meme ber releasable to rotate saidtrip-membertor a.

second position in which said trip-membenperzmits collapse :of saidtoggle to .effect automatic. opening movement of said switch'actuating'meme; her, and atrip device-operable -in:resp0nse:to;:overload currents to release said springroperatedg member.-

11. A circuit breakerrcomprising stationary and." movable contacts, aswitch'actuating member? movable to open andclose said contacts;varlink; having one ,end pivotally mounted on a fixed:- pivot-and theother end pivotally connected. to:- said movable switch actuatingmemberto-form-avtoggle, an operating handle movable-to an; open"position and toa closed position .to-manuallyvopen and close saidcontacts, an overcenter spring connected. to said handle and to saidswitchractuating member operable by said handle "to cause opening andclosing movement of said 3 switch: actuating member, a rotatable-tripmember have ing a,first position in which it cooperatesrwithv the kneeof .said toggle tonormally.restrainrsaid" insaid first positionrestraining ;the kneeof said toggle stationary during manual operation.of. said switch actuating member, a. spring operatedmember releasable torotate saidtrip membertoasecond position in which-saidtrip member per-.-mits collapse :of said toggle to, efiect automatic: opening movement ofsaid switch actuating meme. her free of'said handle, anda trip deviceaoperrable in response to overload currents to release saidspringoperated member, said handle-when. moved to said open positionengaging androtat-- ing said trip member back to said first position.

FRANCIS L. GELZHEISER.

References. Cited in thefile of this patent UNITED STATES PATENTS NumberName Date 1,610,213 De Ville Dec. 7, 1926* 2,214,695 Jennings Sept. 10,1940 2,449,486" Killian et a1 Sept. 14, 1948. 2,494,868 Geremia Jan; 17;1950

